In search for selective anti-insect agents some monoand bis-isothiocyanates were prepared and tested on third instar larvae of Manduca sexta. The alkylene-bis-isothiocyanates 4, 5 and 6 had a novel effect preventing formation of the abdominal spiracles and of the hooks (crochets) at the following molt to the 4th instar. Some of these larvae died in the molt, while spiracles remained absent also...

Over ajbz, I-yearperi'oda range of"ewplantgrowih regularors was tes!ed. or'Ihese onlyAl"G showed any realpromise a detailed report on Ihisprodwc!is avqi7ab/e elsewhere in !heseproceedi'rigs. Work on Pix coi!/71med Iha!short deterinmate culli'vars such as S40 are particularly sensi'ti^e 10 the mappropri'atoprogram apptrca!10n of PI:x, SI!ff'err'rigyie/d losses of between 5 i0 21% when PI::cis us...

Introduction In an earlier publication (2) a comparison was made of the growth regulating activites of various compounds as indicated by the elongation of sections of Avena coleoptiles. From this comparison it was seen that the substitution of various halogen atoms in the phenoxyacetic acid (POA) structure increased its effect on elongation except when both ortho positions were occupied. Also, ...

In recent years exciting progress has been made in understanding how endogenous plant hormones control plant development. One of the fundamental questions in this area of research is the mechanism by which the presente of a plant hormone molecule (the signal) leads to a change in plant development (the transduction pathway). This Update will discuss progress in the genetic analysis of signal tr...

The dynamic patterning of the plant hormone auxin and its efflux facilitator the PIN protein are the key regulators for the spatial and temporal organization of plant development. In particular auxin induces the polar localization of its own efflux facilitator. Due to this positive feedback, auxin flow is directed and patterns of auxin and PIN arise. During the earliest stage of vein initiation...

Soil drying and re-wetting (DRW) occurs at varying frequencies and intensities during crop production, and is deliberately used in water-saving irrigation techniques that aim to enhance crop water use efficiency. Soil drying not only limits root water uptake which can (but not always) perturb shoot water status, but also alters root synthesis of phytohormones and their transport to shoots to re...